Furuno GP-1650WDF manual Measuring Depth, Suppressing Interference, Suppressing Low Level Noise

2.7Measuring Depth

The VRM functions to measure the depth to fish schools, etc., and it is always displayed.

1.Press ▲ or ▼ to shift the VRM.

2.Read the depth just above the VRM.

VRM Depth to VRM

		SOUNDER
	17.5	RANGE
30		20
		GAIN
20		30
		SHIFT
10		40
		MODE/
0		FREQ
		50
42.0
		SNDR
GPS 3D
	50k	FUNC

How to use the VRM

Note: This function is not available on the plotter/sounder display.

2.8Suppressing Interference

Interference from other acoustic equipment operating nearby or other electronic equipment on your boat may show itself on the display as shown in the illustration at the top of the next column.

To suppress interference, do the following:

1.Press the [MENU] key and the SOUNDER SETUP OPTIONS soft key.

2.Select NOISE LIMITER and press the EDIT soft key to show the noise limiter window.

NOISE LIMITER

▲

OFF

NL1

NL2

NL3

▼

Noise limiter window

2.VIDEO SOUNDER OPERATION

3.Press ▲ or ▼ to select degree of suppression desired; OFF, NL1, NL2 or NL3. The higher the number the greater the degree of suppression.

4.Press the RETURN soft key and the [SNDR] key to finish.

Interference from	Electrical inteference
other sounder

Types of interference

Turn the noise limiter circuit off when no interference exists, otherwise weak echoes may be missed.

2.9Suppressing Low Level Noise

Light-blue dots may appear over most of screen. This is mainly due to dirty water or noise. This noise can be suppressed by adjusting CLUTTER on the SOUNDER SETUP OPTIONS menu.

When the sounder mode is Auto, the clutter suppression setting is fixed at AUTO. To suppress low level noise in manual sounder operation do the following:

1.Press the [MENU] key and the SOUNDER SETUP OPTIONS soft key.

2.Select CLUTTER and press the EDIT soft key to show the clutter window.

CLUTTER

▲

3

▼

Clutter window

2-7